The George Zimmerman trial got off to a fierce start on Monday, and an inappropriate joke by the defense attorney has been receiving huge criticism on the Internet.

The "knock knock" joke by defense attorney Don West was made during Monday's opening statements, but was met by a stunned silence as most in the courtroom could not believe the defense was starting the trial with a joke.

West said to jurors: "Knock knock. Who's there? George Zimmerman. George Zimmerman who? Good, you're on the jury."

The joke was rebuked widely on social media sites from those following the trial, and later West apologized for the faltering start from the defense team.

"No more bad jokes, I promise that," he told jurors.

With his joke met with stone cold silence, West awkwardly moved on to the real business of the case. The defense team opened by submitting that Zimmerman was forced to act in self-defense to save his own life, which they claimed was under threat from victim Trayvon Martin.

He said, "The evidence will show this is a sad case; no monsters here. ... George Zimmerman is not guilty of murder. He shot Trayvon Martin after he was viciously attacked."

West told jurors: "Little did George Zimmerman know at the time in less than 10 minutes from him first seeing Travyon Martin that he, George Zimmerman, would be suckered punched in the face, have his head pounded on concrete and wind up shooting and tragically killing Trayvon Martin."

The defense attorney also quoted one eye witness to the attack called John Good who saw part of the fight taking place between Martin and Zimmerman: "He called it a 'ground and pound' by Martin, who he said was on top of Zimmerman, beating him."

West claimed that Zimmerman cried out to Good for help, but that Good rather than getting involved, ran back into his house to call 911.

Soon after that there was a gunshot heard, and West described that when Good came back Zimmerman told him that Martin "was beating me up, and I shot him."

West also rebuked suggestions that Martin was unarmed in the attack: "Travyon Martin armed himself with the concrete sidewalk and used it to smash George Zimmerman's head. No different than if he picked up a brick or smashed his head against a wall. That is a deadly weapon."

West showed photos of Zimmerman after the altercation: "The big knots on each side of his head. Consistent with having his head slammed into concrete."

Earlier the prosecuting attorney John Guy had opened the case rolling off a number of expletives. He said to the jurors: "Good morning. 'F*****g punks, these a******s all get away'."

He then made it clear that he was quoting Zimmerman: "These were the words in this grown man's mouth as he followed this boy that he didn't know. Those were his words, not mine."

He claimed that "[Zimmerman] got out of his car with a pistol and two flashlights to follow Trayvon Benjamin Martin, who was walking home from a 7-Eleven."

Guy also said, "The defendant claims that while Trayvon Martin was on top of him, he said, 'you are going to die tonight…Nobody heard that."

He insisted that no witnesses saw what happened the night of the shooting in its entirety, but only saw "slices" of what occurred between Martin and Zimmerman.

He said, "We are confident that at the end of this trial you will know in your head, in your heart, in your stomach that George Zimmerman did not shoot Trayvon Martin because he had to. He shot him for the worst of all reasons, because he wanted to."